Solar Energy or Solar Heating
project is a collection of science experiments you can use as a
science project for your upcoming science fair. This project is
simple, quick and very educational. The experiments on this project
will help you observe how concave/ converging mirrors collect and
concentrate the solar radiations in one small point. You will also
learn how different colors affect the amount of heat an object may
absorb from the sunlight. Most experiments in this project have
measurable results that can be used to create a data table and a
graph. The experiments for this project may be performed outdoor in
a sunny location or indoor if sunlight is entering trough a clear
glass window. We recommend indoor experiments if the weather is cold
or windy.

Materials:

This solar energy (Solar
Heating) science set contains the following:

Wooden stand with a
16" wooden rod

Glass thermometer
(Basic Laboratory Grade*)

Concave/ converging
Mirror

5 Plastic Test Tube

*Note: You cannot use a
medical thermometer for this project.

Additional Materials you will
need include:

Food coloring or color paper

Watch, clock or timer

Paper and pen to record your
results

Sunlight

WARNING: Adult supervision and
support is required for all experiments and for handling the
materials. Do not leave your experiment setup unattended.

How to use a thermometer?

The thermometer has a red bulb
filled with red liquid and a narrow column of red liquid above that.
The level of liquid in the narrow tube shows the temperature. To
measure the temperature, the bulb of the thermometer must be
inserted in the space or the liquid you want to measure its
temperature. Changes are fairly quick. About 5 seconds after the
movement of the red column stops, you can record the temperature.

List of Experiments:

Efficiency of solar heaters

Solar energy in different
times of the day

Effect of color in absorbing
solar energy

Experiment 1: Efficiency of solar heaters

Introduction: In a solar heater we
use reflectors to concentrate the solar energy in one small point
where we want to cook something or collect and store the heat
energy. In this experiment we want to see how efficient a solar
energy collector is. To do this we will compare the natural heat of
sunlight with the heat collected by a solar heater.

Procedure:

Mount the wooden rod on the
stand

Cut three pieces of 3" x 3"
black paper and roll them around a pencil and then insert each
rolled paper in one test tube. (You use the black paper or black
color
because other experiments have shown that black color will
absorb the most heat from the sunlight)

Use two rubber bands or tape
to attach one of the blackened test tubes (without cap) to the
middle of the wooden rod. Place the stand in a sunny spot and
use the concave side of the mirror to reflect the sunlight
toward the lower/ blackened part of the test tube on the rod.
Make sure the light is focused on the test tube. Secure the
mirror in that position so that it will stay focusing. Readjust
it every 5 minutes if needed.

Use two rubber bands or tape
to attach the second blackened test tubes (without cap) to the
outside wall of a cup or a similar object so that the test tube
can stand vertically. Keep this test tube in the shade.

Use two rubber bands or tape
to attach the second blackened test tubes (without cap) to the
outside wall of a cup or a similar object so that the test tube
can stand vertically. Keep this test tube in a sunny spot.

fill each test tube up to 1/2
with tap water.

After 30 minutes record the
temperature of all 3 test tubes and record your results. Your
data table may look like this:

Location/ Energy
source

Temperature

Shade

20ºC

Direct Sunlight

25ºC

Sunlight collected by
converging mirror

68ºC

You can later use your data in the
above table to calculate the ratio of solar energy collected with or
without the converging mirror.

To calculate the efficiency of your
solar heater with converging mirror you can divide the temperature
increase by the temperature increase in direct sunlight. To show you
an example we have entered some sample data in the table. (Sample
data are not reliable).

Location/ Energy
source

Temperature

Temperature
Increase

Ratio/ Efficiency

Shade

20ºC

0ºC

Direct Sunlight

25ºC

5ºC

1

Sunlight collected by
converging mirror

68ºC

48ºC

9.6

Based on
the above sample data, the temperature increase in
direct sunlight is 5 degrees Celsius, while the
temperature increase with converging mirror is 48º
Celsius. We divide 48 by 5 and get 9.6 as the efficiency
of our solar collector with converging mirror. This
simply means that your converging mirror can increase
the collected energy 9.6 times in compare to direct
sunlight.

Diagram in the right shows how parallel sun rays
converge into a small hot spot.

Make a graph:

You can use a bar
graph to present your results. Make one vertical bar for each of the
three test tubes. The height of each bar will represent the maximum
temperature in each test tube. For example you may make a bar that
is 20 mm tall to represent 20º Celsius temperature.

Shade

Direct
Sunlight

Converged
Sunlight

Experiment 2: Solar energy
in different times of the day

Introduction:
The angle of the sun changes in different times of the day. Other
factors such as cloud may also affect the amount of solar energy we
collect each day. In this experiment you will study the changes in
solar energy in different times of the day. This will help you know
what hours of the day you can collect the highest amount of solar
energy. If the weather is cold or windy, you must perform your
experiment indoor in a glass house/ greenhouse.

Procedure:

Start your experiment in the
morning (after sunrise). Mount the wooden rod on the
stand

Cut one piece of 3" x 3" black
paper and roll it around a pencil and then insert it in one test
tube. (You use the black paper or black color
because other experiments have shown that black color will
absorb the most heat from the sunlight)

Use two rubber bands or tape
to attach the test tube (without cap) to the
middle of the wooden rod. Place the stand in a sunny spot and
use the concave side of the mirror to reflect the sunlight
toward the lower/ blackened part of the test tube on the rod.
Make sure the light is focused on the test tube. Secure the
mirror in that position so that it will stay focusing. Readjust
it every 5 minutes if needed.

Record the temperature of
water every 30 minutes.

Measure and record the
temperature of water in the test tube every 30 minutes and
continue your observations until the late afternoon (sunset).

Time

6

7

8

9

10

11

12

1

2

3

4

5

6

Temperature

You can also use the
above data table to draw a bar graph.

Experiment 3: Effect of color in absorbing
solar energy

Introduction:
The color of a substance certainly affect the amount of heat energy
an object receives from the sunlight. That is why in winter we wear
dark clothes and in summer we put on light color clothes. We are
wondering how effective is the color in absorbing energy and what is
the best color for a solar energy collector. In this experiment you
will make at least one trial for each color.